A Fuzzy Logic-Based Approach for Handling Uncertain EOL Options in Product Design Stage

Today, companies must consider sustainability in addition to their own primary requirements (e.g., cost saving) and to outside constraints (e.g., environmental protection). End-of-life (EOL) option has emerged as a critical factor in sustainability. However, determining EOL options at the product design stage is complicated. For example, designstage EOL options for retired bicycle components are various, and change with geographic location. Therefore, fixed EOL options in the design stage may not always be appropriate; thus, uncertain EOL options should be considered. Limited research exists discussing uncertainty in EOL options at the design stage, and this fact motivates this investigation. In our proposed approach, fuzzy logic is employed to handle uncertainty. The probability of each EOL option is determined by aggregating fuzzy set operations and left-right hand fuzzy rank method. An expected value is derived to represent sustainability value of EOL options. Coffee maker is used as a case study to illustrate the methodology.